It is known that certain elastic synthetic materials cannot be connected to one another unproblematically. For example, it is not possible to connect a silicone layer and a polyurethane layer to one another directly or with adhesives. The coating of silicone is therefore always problematic.
There is a similar problem with the coating of thermoplastic elastomers, as are formed, for example, on the basis of styrene-isoprene-butadiene block copolymers or styrene-ethylene/butylene copolymers. These thermoplastic elastomers (TPEs) may have a high oil content, making surface-area connection to other materials problematic.
US 2009/0240344 A1 discloses a connection of the materials by a textile intermediate layer that can be connected to both materials. However, the laminate formed loses flexibility as a result. In addition, the layer thickness is increased. It is also known from the same document to provide one of the layers with a textured surface, for example in the form of numerous hooks, in order in this way to achieve a mechanical anchoring of the layer of the other synthetic material that is subsequently poured on. Such a method is complex.
DE 26 17 678 A1 discloses producing a polymer composite material from two polymeric components, one of which is a vulcanized rubber and the other is a different vulcanized rubber or a plastic. The connection of the polymeric components is established by a particulate binder layer that predominantly contains particles of carbon and/or a silicon compound being provided at the interface of the components. This layer is penetrated by both components.
DE 10 2008 063 818 A1 discloses providing an orthopedic pad of a fluid-filled elastomer, an elastomer gel, a plasticized thermoplastic or a polyurethane with a friction-reducing layer by subjecting the fully polymerized pad at least to a pretreatment step in which volatile constituents are extracted from the surface and the pad is subsequently coated with a non-polar polymer coating that increases the surface slip. The polymeric coating material may in this case be poly(para-xylylene) (common trivial name: parylene).